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SUWANVARA LAWFIRM
Suwanvara Law Firm Co., Ltd.
SUWANVARA LAWFIRM
SUWANVARA LAWFIRM
Suwanvara Law Firm Co., Ltd.
Intellectual Property

Patent, Petty Patent, or Trade Secret — Which Should You Choose?

Before asking how to file a patent, you must first answer whether you should file at all — the differences between patents, petty patents, and trade secrets, the trap of disclosure before filing, who owns an employee's invention, and what to do when you are copied.

Suwanvara Law FirmIntellectual Property TeamAugust 11, 20267 min read

The most frequently asked question from clients is “how to file a patent,” when the real first question is actually “whether this matter should be filed or not” because filing a patent application means agreeing to disclose the details of your idea to the public in exchange for an exclusive right with a limited duration. If what you have is a formula or process that competitors cannot reverse-engineer, disclosure may be giving it away for free.

This guide answers three questions that are hard to fix once decided wrongly: which method of protection to use, who is the owner, and what evidence to keep before being copied.

Three Alternatives That Do Not Replace One Another

Thailand has three types of patents under the patent law: invention patents for inventions or technical processes, petty patents for inventions with a more relaxed inventive step requirement, and product design patents, which protect external shape or appearance, not functionality. As for trade secrets, no registration is required, but protection is only available as long as the information remains genuinely secret and reasonable measures are taken to maintain it.

Invention PatentPetty PatentDesign PatentTrade Secret
Must be disclosed to the publicYesYesYesNo
Examination before grantStrictestNot fully substantive from the startExamines design and noveltyNo registration
What is protectedWorking principle, processImproved working principleExternal appearanceThe information still secret
Duration of protectionFixed termShorter fixed termFixed termAs long as it remains secret
Competitors can reverse engineerStill cannot infringeStill cannot infringeStill cannot infringeProtection ends

The last row is the heart of the choice. If competitors buy the product, take it apart, and learn how it is made, a trade secret will not help at all when they independently and in good faith arrive at the same solution. Such a product should be patented. As for compound formulas or production parameters that cannot be discerned from the finished product, keeping them secret is usually more advantageous, because the protection never expires and you do not have to tell competitors how you do it.

The trap that cannot be fixed retroactively: disclosure before filing

This is the most common damage, and it is damage that a lawyer cannot remedy once it has occurred.

A key condition for patent applications is novelty. Disclosing the substance of an invention to the public before the filing date may make the invention lack novelty and may lead to rejection, or to revocation later even after registration has been granted. The law provides exceptions for certain types of disclosure within a limited time period, which must be assessed on a case-by-case basis based on the actual date and nature of the disclosure.

Things entrepreneurs often do without realizing that they constitute disclosure include: setting up booths at trade shows, posting demonstration clips on social media, opening pre-orders, sending samples to customers without a confidentiality agreement, submitting price quotations with detailed specifications to several parties, or having the press cover a product launch. The safe sequence is to file the application first, then launch. If you need to talk to factories, investors, or business partners before filing, a confidentiality agreement is required that specifies the scope of the information, the duration, and a prohibition against filing for rights in one's own name.

First to File, Not First to Invent

The Thai patent system prioritizes the filing date. Proving that you conceived of the idea first does not mean you will obtain the rights if another party filed first. In practice, the result is that those who hesitate for months waiting for their product to "settle" often lose their rights to business partners or former employees who filed before them. At that point, the only remaining remedy is to challenge the validity of the other party's application, which is more expensive and slower than filing early.

This issue ties in with deciding who holds the brand from the time of company formation, because it is the same kind of mistake: letting the rights fall to the person who handled the paperwork rather than the person who made the investment.

Who Owns What the Team Creates

As a general rule, for inventions made by an employee under an employment contract or as assigned by the employer, the right to apply for a patent typically belongs to the employer, unless otherwise agreed. The inventor still has the right to be named as the inventor and may be entitled to remuneration under the conditions prescribed by law. Independent contractors who are not employees are not automatically subject to the same principle.

The most common mistake is when a business hires a freelancer, designer, or development company to design a product, pays in full, and assumes it owns the work, even though there is no transfer of rights clause in the quotation or contract at all. When selling the business or bringing in investors, the reviewing lawyers will ask for the chain of title, and this gap can genuinely stall the deal.

What should be in the documents before work begins — not after it ends — is: an agreement that the work product and inventions arising from the engagement belong to the client; an obligation for the inventor to sign any documents necessary for subsequent filings; a confidentiality clause that remains in effect after the engagement ends; and a restriction on reusing the work for other clients.

A Patent Is Not a License to Sell

The misunderstanding that causes businesses to waste time and money repeatedly is thinking that once a patent is obtained, the product can be sold right away. The truth is that a patent gives you the power to prohibit others from using your invention, but it does not give you the right to sell the product while bypassing other laws. Products subject to mandatory standards still require an industrial standards license (Do products require a มอก. (Thai Industrial Standard)? Who is liable?); cosmetics still require notification (Cosmetic notification (ใบจดแจ้ง): who should hold it?); and having your own patent does not mean your product will not infringe someone else's patent — that is a separate question and must be checked separately.

What to Do When Your Patent Is Copied

Patent disputes fall within the jurisdiction of the Intellectual Property and International Trade Court, not the general civil courts. A case may include a civil component for damages and injunctive relief, as well as a criminal component, depending on the nature of the act.

What determines the outcome of a case is often not the law, but the evidence gathered before the other party becomes aware: the other party's product actually purchased, complete with receipts and order evidence; the online storefront recorded in full, with date and time; seller details and shipping channels; and a technical comparison between the other party's product and your patent claims, claim by claim. Sending a warning letter before the evidence is complete is a warning to the other party to hide the goods, and immediately weakens the case.

If the copying was committed by former employees or business partners who had previously seen internal information, the case may be brought on both grounds of patent infringement and trade secret disclosure simultaneously. These require different sets of documents, so you should have a lawyer plan the case strategy before contacting the other party.

Registering in Thailand Does Not Mean Protection Worldwide

A patent has effect only in the country where it is registered. Those who intend to export or manufacture abroad must decide on target countries from the time of the first filing, because the right to claim priority back to the first filing date is available only within a prescribed time limit. Once that period has lapsed, later-filed applications may be challenged for lack of novelty on the basis of documents that have already been published, including your own documents.

Checklist before starting

  • Clearly specify what will be protected — the working principle, the appearance, or information that must not leak — because these three things use different tools.
  • Check whether it has already been publicly disclosed, along with the date and channel, before spending money on drafting the application.
  • Search existing patent information to see both whether yours is new enough and whether it will conflict with anyone else's.
  • Keep development notebooks, design files with dates and times, and lists of co-inventors from the start.
  • Close the gaps in contracts with employees, freelancers, contract manufacturers, and business partners so that they include both assignment of rights and confidentiality clauses.
  • Decide on target countries at the same time as the first filing, not when the product is selling well.

Summary

Choosing between filing for a patent and keeping the invention as a trade secret is a business decision determined by a single question: can competitors reverse-engineer it? Meanwhile, all irreparable damage stems from two issues: disclosing the invention before filing, and having no documentation of who owns it. Both can be prevented with just a few documents prepared before work begins.

Suwanvara Law Firm offers rights status checks, structures intellectual property ownership in employment and manufacturing contracts, drafts confidentiality agreements, and handles litigation in the Intellectual Property and International Trade Court. Consult the intellectual property team or see intellectual property services.

This content is general information for understanding purposes only and is not legal advice for any specific case. Protection and timelines depend on the facts of each matter; you should therefore consult a lawyer before making a decision.

Frequently asked questions

Can I still file a patent after exhibiting or posting the product for sale?+

Consult a lawyer immediately, because a key requirement for a patent is novelty. Disclosing the substance of the invention to the public before filing — whether through exhibiting, posting on social media, offering for sale, or media coverage — may make the invention no longer new and cause it to be rejected or later revoked. The law has exceptions for certain types of disclosure within a very limited time period, so a lawyer must review the actual dates and nature of the disclosure before concluding whether you can still file.

What is the difference between a petty patent and an invention patent?+

An invention patent requires substantive examination before it is granted, so it takes longer but is more secure once obtained. A petty patent applies a more relaxed inventive step threshold and is registered faster because it is not fully examined from the beginning. However, interested parties may later request examination and challenge its validity. A petty patent is therefore suitable for technical improvements with short product cycles, not a shortcut for inventions intended to be held for a long time.

If an employee or freelancer created the invention, who owns the patent?+

As a general rule, for an invention made by an employee in the course of duties or under the employer's assignment, the right to apply for a patent usually belongs to the employer, unless agreed otherwise. The inventor still has the right to be named and may be entitled to remuneration under conditions provided by law. An independent contractor is not an employee, so this rule does not automatically apply. Without a clear assignment-of-rights clause in the contract, the client may not be the owner as they expect.

If I file a patent in Thailand, does it protect me abroad?+

No. A patent is protected only in the country where it is registered. To obtain protection in another country, you must file there within the deadline that allows you to claim the priority date of your first filing. Anyone planning to export should therefore decide on target countries at the time of the first filing, not when the product starts selling well.

If my product is copied, which court should I sue in?+

Patent and intellectual property disputes fall under the jurisdiction of the Intellectual Property and International Trade Court, not ordinary civil courts. The case may have a civil element to claim damages and a criminal element depending on the nature of the conduct. What you need to prepare from the first day is evidence of your right, evidence of the other party's actions, and evidence of damage, which generally must be secured before the other party realizes.